PSORIASIS · White paper
Psoriasis Clinical Trials
Approved therapies, the pivotal-trial endpoints they were judged on, the magnitude of benefit — and the drugs that failed their endpoints, and why.
Indication overview
About psoriasis — and why its trials are hard
Psoriasis is a chronic, immune-mediated skin disease driven by dysregulated T cells and cytokines such as TNF, IL-17, and IL-23, most often presenting as plaque psoriasis with red, scaly lesions on the scalp, elbows, knees, and back. The recognition of psoriasis as an immune-mediated condition redirected drug development from purely symptomatic topical therapy toward targeted biologics and oral small molecules. Modern clinical trials are anchored on the Psoriasis Area and Severity Index (PASI 75/90/100) and Investigator/static Physician's Global Assessment (IGA/sPGA), supplemented by quality-of-life measures like the DLQI. Successive drug classes have raised the efficacy bar: TNF inhibitors and ustekinumab (IL-12/23), then IL-17 inhibitors (secukinumab, ixekizumab, brodalumab, bimekizumab), IL-23 inhibitors (guselkumab, risankizumab), the oral TYK2 inhibitor deucravacitinib, and the PDE4 inhibitor apremilast. Key trial challenges include scoring subjectivity, blinding of topicals, disease heterogeneity, relapse and flare management, and acquired biologic resistance over time.
Approved therapies & pivotal evidence
What's been approved — and by how much it moved the endpoint
| Drug (brand) | Approved | Setting | Pivotal trial | Primary endpoint | Magnitude of benefit |
|---|---|---|---|---|---|
| Secukinumab (Cosentyx) | 2015 | Moderate-to-severe plaque psoriasis (IL-17A inhibitor) | ERASURE / FIXTURE (PsO trials) | PASI 75, IGA 0/1 | PASI 75 ~82% (300 mg) vs ~4% placebo at Week 12 |
| Ixekizumab (Taltz) | 2016 | Moderate-to-severe plaque psoriasis (IL-17A inhibitor) | UNCOVER-1/2/3 | PASI 75/90/100, sPGA 0/1 | PASI 75 ~87-89% vs ~4% placebo; PASI 90 ~68-71% at Week 12 |
| Brodalumab (Siliq) | 2017 | Moderate-to-severe plaque psoriasis (IL-17 receptor A inhibitor) | AMAGINE (Trials 1-3) | PASI 75/100, sPGA success | PASI 75 83-86% vs 3-8% placebo; PASI 100 37-44% |
| Deucravacitinib (Sotyktu) | 2022 | Moderate-to-severe plaque psoriasis (oral TYK2 inhibitor) | POETYK PSO-1 & PSO-2 | PASI 75, sPGA 0/1 (vs placebo and apremilast) | Superior to placebo and apremilast on PASI 75/sPGA at Week 16 (n=1,684) |
| Bimekizumab (Bimzelx) | 2023 | Moderate-to-severe plaque psoriasis (IL-17A and IL-17F inhibitor) | BE VIVID / BE READY / BE SURE | PASI 90/100, sPGA 0/1 | High PASI 90/100 response maintained to Week 52-56; superior to adalimumab |
| Adalimumab (Humira) | 2008 | Moderate-to-severe plaque psoriasis (TNF-alpha inhibitor) | REVEAL | PASI 75, PGA | PASI 75 ~71% vs ~7% placebo at Week 16 |
Where trials have failed
Drugs that missed their endpoint — and what contributed
The most instructive lessons in psoriasis development come from programmes that failed the endpoint that mattered.
| Drug / trial | Endpoint outcome | What contributed |
|---|---|---|
| Adalimumab (OSA subpopulation) — NCT01181570 | No improvement in psoriasis among subjects with obstructive sleep apnea | Comorbid population and confounding limited demonstrable benefit |
| Voclosporin — NCT00408187 | Not statistically non-inferior to cyclosporine in efficacy | Failed to demonstrate comparable efficacy versus active comparator |
| Infliximab — NCT00358670 | Trial terminated due to adverse events | Safety/tolerability signals prompting early termination |
Choosing the right endpoint
Primary endpoints that matter in psoriasis trials
- PASI 75 / 90 / 100 — Proportion achieving 75%, 90%, or 100% reduction in Psoriasis Area and Severity Index; the primary efficacy standard, with PASI 90/100 now expected for newer IL-17/IL-23 agents
- IGA / sPGA 0 or 1 — Clear or almost-clear on a static global assessment; common co-primary endpoint for FDA approval
- Body Surface Area (BSA) — Percentage of body affected; intuitive but less granular than PASI and prone to visual-estimate imprecision
- DLQI — Dermatology Life Quality Index; patient-reported quality-of-life measure over the prior week, subject to cultural and perceptual variability
- Itch NRS — Numeric rating scale for itch; patient-reported symptom endpoint (e.g., >=4-point reduction) capturing a key burden
How iNGENū runs psoriasis trials
Physician-led design, built for FDA submission
Endpoint & biomarker strategy
Board-certified specialists design endpoints and patient selection aligned to current FDA guidance for this indication.
FDA-ready data
Built to ICH-GCP and 21 CFR 312.120, with direct FDA submission — data accepted by the FDA, EMA and MHRA.
Faster, lower-cost delivery
~4-week ethics via the TGA CTN scheme, up to 43.5% R&D rebate, and 80–90% below US CRO cost.
The full white paper: approved-product analyses, pivotal endpoints and trial-design strategy. Open-access · no sign-in.
Frequently asked questions
Psoriasis clinical trials — FAQs
What is the primary efficacy endpoint in psoriasis trials?
How do the main drug classes for psoriasis differ?
Why is blinding difficult in psoriasis trials?
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